This is the second renewal application of a training program designed to produce investigators at the cutting edge of basic and clinical research in the area of pediatric gastroenterology. Trainees will be at the postdoctoral level and will be a mixture of M.D.?s and Ph.D.?s supported for 33 mos. and 2 yr., respectively. To allow recruitment of one new M.D. and Ph.D. trainee each year, a total of 3 M.D. stipends and 2 Ph.D. stipends are requested. For all trainees, the program places strong emphasis on molecular biology, the rationale being that molecular approaches have become increasingly important in both investigation and treatment of diseases associated with pediatric gastroenterology. The mentors (5 M.D.?s, one M.D., Ph.D. and 7 Ph.D.?s) represent a multidisciplinary group of experienced scientists from various departments at Baylor. All study questions that are important to pediatric gastroenterology. Eleven of the 13 mentors work at the molecular level and the remaining two are clinical investigators. All laboratories are well equipped and well funded. All 13 faculty members are already associated with the program and have excellent track records of interaction and participation in program activities. The Program Director maintains ultimate authority for the overall program and manages day-to-day operations. Major administrative decisions (e.g., selection of trainees) are handled by an Executive Committee, which is chaired by the Division Chief and includes 4 of the mentors as well as a senior faculty member not associated with this grant. The training program for M.D. fellows includes research rotations to facilitate selection of a mentor, an individual research committee, a written research proposal which has to be defended to that committee, and periodic reviews of progress. Trainees are selected from a highly competitive applicant pool that already exists at Baylor College of Medicine. Past trainees have performed well with 83% of M.D.?s and 75% of Ph.D.?s remaining active in research and having a variety of funding including F32, K08 and R01 The proposal includes several new features designed to enrich and enhance the existing program.